Financial Instruments (Details)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Jun. 30, 2013 USD ($)	Jun. 30, 2012 USD ($)	Dec. 31, 2012 USD ($)	Jun. 30, 2013 Equity Contract [Member] USD ($)	Jun. 30, 2013 Equity Contract [Member] USD ($)	Jun. 30, 2012 Equity Contract [Member] USD ($)	Jun. 30, 2013 Hedged Fixed-Rate Debt [Member] USD ($)	Jun. 30, 2012 Hedged Fixed-Rate Debt [Member] USD ($)	Jun. 30, 2013 Hedged Fixed-Rate Debt [Member] USD ($)	Jun. 30, 2012 Hedged Fixed-Rate Debt [Member] USD ($)	Jun. 30, 2013 Interest Rate Contract [Member] USD ($)	Jun. 30, 2012 Interest Rate Contract [Member] USD ($)	Jun. 30, 2013 Interest Rate Contract [Member] USD ($)	Jun. 30, 2012 Interest Rate Contract [Member] USD ($)	Jun. 30, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Jun. 30, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Jun. 30, 2013 Carrying (Reported) Amount, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Jun. 30, 2013 Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2012 Fair Value, Inputs, Level 1 [Member] USD ($)	Jun. 30, 2013 Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 Fair Value, Inputs, Level 2 [Member] Equity Contract [Member] USD ($)	Jun. 30, 2013 Fair Value, Inputs, Level 2 [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member] Interest Rate Contract [Member] USD ($)	Jun. 30, 2013 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2012 Fair Value, Inputs, Level 2 [Member] Foreign Exchange Contract [Member] USD ($)	Jun. 30, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Equity Contract [Member] USD ($)	Jun. 30, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Interest Rate Contract [Member] USD ($)	Jun. 30, 2013 Estimate of Fair Value, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Dec. 31, 2012 Estimate of Fair Value, Fair Value Disclosure [Member] Foreign Exchange Contract [Member] USD ($)	Jun. 30, 2013 Corporate Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Corporate Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Corporate Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Corporate Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Corporate Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 Corporate Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 Corporate Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Corporate Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 US Government Agencies Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 US Government Agencies Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 US Government Agencies Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 US Government Agencies Debt Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2012 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Jun. 30, 2013 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 US Government Agencies Debt Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 US Government Agencies Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 US Government Agencies Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Other Debt Obligations [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Other Debt Obligations [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Other Debt Obligations [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Other Debt Obligations [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Other Debt Obligations [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 Other Debt Obligations [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 Other Debt Obligations [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Other Debt Obligations [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Collateralized Mortgage Backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Collateralized Mortgage Backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Collateralized Mortgage Backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Collateralized Mortgage Backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Collateralized Mortgage Backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 Collateralized Mortgage Backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 Collateralized Mortgage Backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Collateralized Mortgage Backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Asset-backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Asset-backed Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Asset-backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Asset-backed Securities [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Asset-backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Dec. 31, 2012 Asset-backed Securities [Member] Fair Value, Inputs, Level 2 [Member] USD ($)	Jun. 30, 2013 Asset-backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Asset-backed Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Equity Securities, US [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Equity Securities, US [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Equity Securities, US [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Equity Securities, US [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Equity Securities, US [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Dec. 31, 2012 Equity Securities, US [Member] Fair Value, Inputs, Level 1 [Member] USD ($)	Jun. 30, 2013 Equity Securities, US [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Equity Securities, US [Member] Estimate of Fair Value, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Equity Method and Other Investments [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Dec. 31, 2012 Equity Method and Other Investments [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] USD ($)	Jun. 30, 2013 Equity Method and Other Investments [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Dec. 31, 2012 Equity Method and Other Investments [Member] Available-for-Sale Securities, Amortized Cost [Member] USD ($)	Jun. 30, 2013 Buy British pound Sell euro [Member] EUR (€)	Jun. 30, 2013 Buy British pound Sell euro [Member] GBP (£)	Jun. 30, 2013 Buy US dollar Sell euro [Member] USD ($)	Jun. 30, 2013 Buy US dollar Sell euro [Member] EUR (€)	Jun. 30, 2013 Buy euro Sell US dollar [Member] USD ($)	Jun. 30, 2013 Buy euro Sell US dollar [Member] EUR (€)	Jun. 30, 2013 Buy US dollar Sell Japanese Yen [Member] USD ($)	Jun. 30, 2013 Buy US dollar Sell Japanese Yen [Member] JPY (¥)	Jun. 30, 2013 Buy euro sell British pound [Member] EUR (€)	Jun. 30, 2013 Buy euro sell British pound [Member] GBP (£)
Available-for-sale Securities, Debt Securities	$ 6,942,800,000		$ 6,942,800,000
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge									144,300,000	97,600,000	213,300,000	31,700,000
Cash and Cash Equivalents, Fair Value Disclosure																	3,786,500,000	4,018,800,000						3,786,500,000	4,018,800,000	3,724,700,000	3,964,400,000	61,800,000	54,400,000						3,786,500,000	4,018,800,000
Long-term Debt																	(5,314,000,000)	(5,531,300,000)										(5,638,100,000)	(5,996,600,000)						(5,638,100,000)	(5,996,600,000)
Derivative Assets, Current																				12,400,000		22,800,000	11,000,000								12,400,000		22,800,000	11,000,000				12,400,000		22,800,000	11,000,000
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Other, Percentage of Nonperforming Assets	80.00%
Maximum Remaining Maturity of Foreign Currency Derivatives	30 days
Description of Derivative Activity Volume Percent	60.00%		60.00%
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments													(144,300,000)	(97,600,000)	(213,300,000)	(31,700,000)
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	8,900,000		8,900,000
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	2,200,000	2,200,000	4,400,000	4,400,000
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(7,600,000)	18,000,000	(7,500,000)	(14,800,000)
Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net						10,100,000	8,900,000	0
Derivative Assets, Noncurrent																			600,000	363,700,000	589,400,000									600,000	363,700,000	589,400,000					600,000	363,700,000	589,400,000
Derivative Liabilities, Current																			(7,300,000)			(5,400,000)	(17,500,000)							(7,300,000)			(5,400,000)	(17,500,000)			(7,300,000)			(5,400,000)	(17,500,000)
Derivative Liabilities, Noncurrent																			(2,200,000)											(2,200,000)							2,200,000
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	4,836,000,000		4,836,000,000
Available-for-sale Securities, Gross Unrealized Gains			182,100,000		140,500,000
Available-for-sale Securities, Gross Unrealized Losses			77,800,000		29,000,000
Available-for-sale Securities, Continuous Unrealized Gain Position, Fair Value	2,768,300,000		2,768,300,000		5,246,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	4,295,500,000		4,295,500,000		2,102,000,000
Other than Temporary Impairment Losses, Investments	0	3,700,000	5,200,000	7,400,000
Proceeds from Sale and Maturity of Available-for-sale Securities	3,587,600,000	1,251,900,000	6,939,700,000	3,635,300,000
Available-for-sale Securities, Gross Realized Gains	28,200,000	13,200,000	38,200,000	26,900,000
Available-for-sale Securities, Gross Realized Losses	5,400,000	2,500,000	7,900,000	5,200,000
Available-for-sale Securities, Current [Abstract]
Available-for-sale Securities, Debt Securities, Current																																										838,300,000	1,503,500,000	836,300,000	1,501,500,000	838,300,000	1,503,500,000	838,300,000	1,503,500,000	84,500,000	150,200,000	84,500,000	150,200,000	84,500,000	150,200,000			84,500,000	150,200,000	1,700,000	11,800,000	1,700,000	11,800,000	1,700,000	11,800,000	1,700,000	11,800,000
Available-for-sale Securities, Current, Total																	924,500,000	1,665,500,000						922,500,000	1,663,500,000
Available-for-sale Securities, Noncurrent [Abstract]
Available-for-sale Securities, Debt Securities, Noncurrent																																										3,948,400,000	3,351,300,000	3,978,100,000	3,322,900,000	3,948,400,000	3,351,300,000	3,948,400,000	3,351,300,000	1,083,700,000	1,362,700,000	1,090,900,000	1,360,300,000	1,001,200,000	1,122,400,000	82,500,000	240,300,000	1,083,700,000	1,362,700,000	7,800,000	3,300,000	8,100,000	3,300,000	7,800,000	3,300,000	7,800,000	3,300,000	629,300,000	668,100,000	646,000,000	677,700,000	629,300,000	668,100,000	629,300,000	668,100,000	353,500,000	519,000,000	358,800,000	523,500,000	353,500,000	519,000,000	353,500,000	519,000,000
Available-for-sale Securities, Equity Securities, Noncurrent																																																																																				262,400,000	175,800,000	100,900,000	83,000,000	262,400,000	175,800,000	262,400,000	175,800,000
Other Long-term Investments																																																																																												276,300,000	233,100,000	276,300,000	233,100,000
Available-for-sale Securities, Noncurrent, Total																	6,561,400,000	6,313,300,000						6,459,100,000	6,203,800,000
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	924,500,000		924,500,000
Available-for-sale Securities, Debt Maturities, Year Six Through Ten, Fair Value	448,800,000		448,800,000
Available-for-sale Securities, Debt Maturities, after Ten Years, Fair Value	733,500,000		733,500,000
Derivative Liability, Notional Amount																																																																																																	251,600,000	895,300,000			192,700,000	323,000,000		170,000,000
Derivative Asset, Notional Amount																																																																																																€ 293,400,000			€ 680,100,000	$ 253,900,000			¥ 31,210,000,000		£ 145,100,000